body {
  font-family: sans-serif;
  background-color: #f4f4f9;
  color: #333;
  margin: 0;
  padding: 20px;
}

.container {
  max-width: 500px;
  margin: 0 auto;
  background: #fff;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

h1 {
  color: #5a5a5a;
  text-align: center;
}

form {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
}

input[type="text"] {
  flex-grow: 1;
  padding: 10px;
  border-radius: 4px;
  border: 1px solid #ccc;
  font-family: sans-serif;
}

button {
  background-color: #007bff;
  color: white;
  padding: 10px 15px;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}

button:disabled {
  background-color: #ccc;
}

.todo-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.todo-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px;
  border-radius: 4px;
  background-color: #f9f9f9;
}

.todo-item.completed span {
  text-decoration: line-through;
  color: #888;
}
